Washable wall covering and method of making the same



Patented Aug. 23, 1938 UNITED STATES PATENT OFFICE WASHABLE WALL COVERING AND METHOD OF MAKING THE SAME George W. Jennings, Chicago, Ill.

No Drawing. Application January 11, 1936, Serial No. 58,755

2 Claims.

5 provide a washable or water resisting covering after ithas been applied to the surface and become dried, and also to the method of mixing or compounding such material.

Wall coverings of somewhat similar character utilizing casein compositions or based on casein have heretofore been proposed or used but such compositions necessarily contain alkalies which injure the brushes used for applying the same. Furthermore such compositions have been found to vary greatly in different batches and as made by different manufacturers due to different grades of milk used in the manufacture of the casein, and also to different methods. of preparing the casein. Furthermore paints embodying such casein compositions dry so hard that they usually crack with age.

One of the particular objects of this invention is to provide a calcimine or paint of the character indicated which will avoid such objectionable features and which may be readily manufactured at a comparatively low cost and may also be readily applied to the surface to be covered and which will thereafter become chemically changed in order to render the same washable or substantially waterproof.

Other objects are to provide a calcimine or paint of the character indicated which contains glue in soluble form and also contains ingredients adapted to tan the glue or render the same insoluble and another ingredient or ingredients which will retard or prevent the action of the tanning ingredients until the calcimine has been applied to the surface; to provide an improved calcimine or cold water paint in which the various ingredients are mixed with water and which will become water-proof upon application, and to the method of making such calcimine or paint; and to provide such other novel features, compositions and methods as will appear more fully from the following description.

A preferred composition embodying my invention consists of a suitable pigment such as a mixture of titanium oxide and silica, glue comprising an animal product, an acid such as glacial acetic acid, formic acid or concentrated hydrochloric acid, sodium acetate, aluminum sulphate, and a vehicle comprising water to make a paste.

In preparing the composition I prefer to use the ingredients in about the following proportions by weight, namely:

Percent Pigment (50% titanium oxide and 50% silica) 50 Water 43 Animal glue 3.5 Glacial acetic acid 2. 2

Sodium acetate 5 Aluminum sulphate .8

Glue may be tanned or rendered insoluble in water by a mixture of sodium acetate and aluminum sulphate and if these ingredients are mixed together such tanning action will occur at once. However, I have discovered that by mixing a suitable acid such as glacial acetic acid or hydrochloric acid with these ingredients, the tanning action is prevented until such acid has evaporated, which will occur after the paint or mixture is spread on the wall. Thereupon the tanning action will proceed to render the glue insoluble and thus provide a washable covering. If concentrated hydrochloric acid is used in the place of acetic acid, approximately four percent (4%) should be used with a consequent reduction in the water content. The above proportions will make a paste or paint which can be applied directly to the surface or it may be diluted or mixed with an additional amount of Water up to approximately of the weight of such mixture.

In preparing the composition I first dissolve the glue in one portion (about 9%) of the water and dissolve the sodium acetate and aluminum sulphate together in another portion (about 1.9%) of the water. The pigment is then mixed with the rest of the water (33.1%). The glue solution is then added to the mixture of pigment and water, then the acid is added thereto, and finally the solution of sodium acetate and sulphate of aluminum is added and the entire mass mixed in any suitable apparatus such as a paint mixing mill or the like. The mixture may then be placed in cans or containers to prevent exposure to the air or evaporation of the acid and is then ready to be applied to the surface or to be diluted with water and applied as above described.

After the paint or covering has been applied to the surface the acid or tanning inhibitor in the solution will gradually evaporate and permit the tanning agents to act upon the glue and tan or coagulate the same and thus produce a composition which may be washed in the usual manner.

In some instances I may add a suitable plasticizer such as linseed oil to the mixture to prevent the film from becoming too brittle and to maintain the plasticity or increase the elasticity and flexibility of the paint. When such plasticizing ingredient is used about 10% may be added in the place of a corresponding amount of the water. I may also provide a preservative such as sodium benzoate to preserve the glue and keep it from spoiling, about .1 of one percent of such preservative being sufiicient for ordinary purposes.

From this description it will be seen that I provide a Washable paint or composition having the novel characteristics set forth and which will not affect the brushes used for applying the same inasmuch as it contains no alkali and will be durable in use and may also be made pleasing in appearance.

It may be noted that changes may be made in the various ingredients in order to adapt the same for different surfaces or conditions or to produce different decorative effects and therefore I do not wish to be limited to the particular method or composition herein described except as set forth in the following claims, in which I claim:

1. A composition for covering surfaces comprising the following ingredients in substantially the proportions set forth,

Per cent by weight Pigment 50 Glue 3.5 Acetic acid, glacial 2. 2 Sodium acetate .5

Aluminum sulphate .8 Water 43 2. The method of making a washable Wall covering which consists in dissolving a sufficient amount of animal glue to make 3.5% by Weight of the entire composition, in water, dissolving sodium acetate .5% and aluminum sulphate .8% in water, mixing pigment 50% in water, then adding the glue solution to the pigment mixture, then adding concentrated hydrochloric acid 4%, and finally adding the solution of sodium acetate and aluminum sulphate, the water content being suificient to make the balance of 100% of the mixture, and thoroughly mixing the ingredients as described.

GEORGE W. JENNINGS. 

